Hmmm. Sounds like you're in a tough spot. Are you in North America? Or elsewhere in Europe? Or down under? This could make a difference. Will both hips be done on the same day? Or a few days apart? How long will you be in the hospital afterwards?
I only had one hip done (so far), and I didn't have to travel out of town for it. However, I do live alone, so I have some idea of the challenges you might face on your own. My most difficult day was my second day post-op, which was my first day home alone. I dropped all my reachers, and didn't even have the energy to nuke a meal. I did get better each day. I expect with a bilateral it would be even worse. Hopefully you would be in the hospital for a few days. After that you'll be on your own in a hotel. (Several people suggested to me in advance of my surgery that I check into a hotel afterwards.) The good news there is maid service and meal service so that these details are taken care of. Hopefully said hotel has handicapped rooms with handicap toilets. You are going to need a raised toilet and handrails. The longer you can stay at said hotel the better. As already mentioned you will be feeling much better and much more able to get around every day. With only my one hip done at ten days post-op my neighbor commented that I was getting around better than he was (he needs a cane).
Still, getting from that hotel to your home will require a lot of help. This will be the most difficult part of the trip. You might need somebody to help you pack your luggage, certainly to lift it from the floor to someplace you can pack it. Someone will need to transport it from your room to a taxi. Someone will need to carry it from the taxi to airline check in. You will need a wheelchair at the airport. I am not sure how to manage the 90 degree rule in a coach seat. If you're got the FF miles, or can afford it, this is the time to upgrade. If you are returning to the US typically you go through customs with your luggage, and I don't know if you can find someone to help you here. After that the luggage usually goes back on the conveyor belt and comes out on the other end where presumably the hubby would take over.
I wouldn't say no. As a single person with no close relatives if that's what I needed to do I would. I would advise thinking through all the steps and making a plan for overcoming the obstacles each one presents. I don't think they're insurmountable, but they will each require advance planning. Asking De Smet's office what others in similar situations have done might be helpful. I'm sure you're not the first in this situation. Perhaps someone local in Belgium can be hired for transport and chores for you.
Since the husband/baby issue presents rather understandable problems, is there the possibility of another family member or friend accompanying you? If they can't be with you the whole time, even if they only come at the end to help you travel back it would be beneficial.